EP0694574A1 - Process for making fire proofing composites - Google Patents

Abstract

The prodn. of fireproof composites (I) from highly conc. intumescent plastisols (II) comprises (1) dispersing the fire retardants (III) in the plasticiser in a high-speed mixer to give a homogeneous paste, opt. cooling, and (2) mixing with synthetic resin in a slow-speed mixer to give (II). Also claimed is (1) prodn. of highly flexible laminated composites (I) by spreading (II) on a flat base strip using a cylinder/blade system, and then gelling/hardening the plastisol by heating; and (2) prodn. of flexible intumescent foam (by cold-foaming (II) with addn. of 2-3 wt.% soap and/or silicone foaming agent and then heat-curing as above). Pref., stage (1) is carried out in a dissolver-mixer at 1000-2000 r.p.m., and stage (2) in a planetary mixer at not more than 100 r.p.m. The plastisol may be filtered and degassed before further processing. Depending on the application, (III) may consist of a mixt. of (a) intumescent, (b) ablative (water-releasing) and opt. also (c) expansion pressure-generating components. Pref. (a) are mainly mixts. based on phosphate, borate or sulphate salts; (b) comprise artinite, aluminohydrocalcite, dansonite, hydrotalcite, Mg(OH)2, zeolites etc. (15 types listed), pref. Al(OH)3 and/or dimelamine pyrophosphate; (c) comprise expanded mica, perlite, raw vermiculite and borophosphates, pref. expanded mica.

Description

The present invention relates to a method for producing fire-protective composite materials using highly concentrated intumescent plastisols and their use in structural fire protection.

Intumescent materials are materials that foam when exposed to heat and form an insulating and fire-resistant foam ("thermal foam") that protects the underlying surfaces and substrates from the effects of fire. In addition to the classic mixture of three carbon dispensers, dehydrating agents and blowing agents, e.g. Sugar, ammonium phosphate and melamine, two-component systems have also been developed such as Melamine phosphate in a mixture with boric acid and increasingly also one-component materials are used. In addition to the well-known alkali silicates "water glass", the latter also include expanded mica, expanded graphite, pearlite, raw vermiculite and others.

The intumescent materials are used in structural fire protection in the form of paints, varnishes, coatings, pastes, putties, mortars, seals, plates, cuts, strips, foams, sheets, foils, profiles, etc. Semi-finished products.

With the use of intumescent materials (also called insulating layer formers), attempts are made to improve the fire resistance of components or special components or to achieve better fire classification of building materials.

From the multitude of currently known intumescent products, a closer examination of the intumescent plastics that have only been known for a few years seems sensible insofar as it can document a relevant delimitation from the known state of the art and thus also the inventive level of the present invention.

Intumescent plastics are either extruded from free-flowing mixtures of fire protection components and thermoplastic matrix into semi-finished products in the form of profiles, strips and webs or calendered in the form of foils (DE 37 27 271 or EP 0 256 967, EP 0 302 987, EP 0 541 504). Thanks to their high flexibility, they can also be used to protect cylindrical, round and spherical components. A useful application can be found in fire protection sleeves or profiles for edge protection. Due to the plastic matrix, they can also be used in these areas where mechanical stress such as pressure, tensile and bending forces affect the products used. When trying to use intumescent foils or sheets to protect large-area vertical elements, such as hazardous goods containers, the limits of this new product group quickly became apparent. The thermoplastic materials are torn open by the action of heat, which necessitates very complex, flat anchoring.

getestet werden müssen.Furthermore, another property of the thermoplastic matrix has a negative impact. It is known that the thermal foam formed under the influence of heat tends to slip under vertical conditions of use. This tendency to slip is different to different degrees in different layers of insulation, but increases in proportion to the foaming factor. These properties, which are known per se, led, among other things, to the fact that intumescent fire protection products are also subjected to the conditions of the so-called temperature-rise curve ${\text{V - V}}_{\text{0}}\text{= 345 lg (8 (t-20) +1)}$

need to be tested.

Tests with large-sized components quickly showed that due to the high proportion of a thermoplastic matrix, the majority of the melting mass flows downwards and an inadmissible temperature increase occurs on the upper part of the test specimen. An obvious recipe change by adding fibrous components is technically not feasible, since these are highly filled masses that are processed at the limit of their flowability.

In order to be able to extrude a mixture with, for example, 0.5% by weight of fibrous components, the other fire-protecting components must be reduced by a factor of 10 to 20. Due to the higher proportion of the melting away plastic matrix, the stabilizing effect achieved by the fibers is canceled again. An additional disadvantage of such armored masses is their increased flammability and the associated poorer fire classification.

Similar problems arise when trying to develop intumescent plastics using the plastisol technique.

A standard PVC plastisol (100 parts by weight of PVC powder, 56 parts by weight of plasticizer and 1.5 parts by weight of stabilizer) can be used under normal circumstances with up to 25% by weight of powdery components fill without significantly affecting the squeegee capability.

In the case of PVC plastisols with a low viscosity, the limit value for the filling is max. 30% by weight. Agglomerates form when mixing higher-filled mixtures in the planetary mixer, which cannot be dissolved even after longer mixing times. Subsequent treatment on the three-roller chair does not result in a perfectly homogeneous mixture. Although this can be achieved by dispersing in the high-speed agitator, only the frictional heat leads to a gelation of the paste, which prevents its processing in knife application, reverse roll-coater coating or rotary screen printing, or at least makes it very difficult.

In addition, the plastic masses produced with these proportions do not even come close to the most important fire protection properties (foaming factor, inflation pressure, fire classification) of the thermoplastic manufactured, highly filled (degree of filling 40 - 60% by weight) fire protection products.

It was therefore an object of the present invention to develop a method with which highly concentrated intumescent plastisols can be provided and used in conjunction with suitable carrier materials for the production of fire-protective composite materials.

In solving this problem, it was unexpectedly found that if plasticizers are first used as a dispersing medium for the powdery components prior to contact with synthetic resin, significantly higher concentrations of the latter can be achieved in the plastisol. The homogenization of the fire protection components is not hindered by the swelling synthetic resin particles.

The invention hereby relates to a process for the production of fire-resistant composite materials using highly concentrated intumescent plastisols, in which the fire protection components are first dispersed in a high-speed mixer into which plasticizers and, if appropriate, other liquid constituents, and the homogeneous paste obtained, if necessary after cooling The addition of synthetic resin in a slow-running mixer is converted into a highly concentrated intumescent plastisol.

Despite the high proportion of fire protection components, these intumescent plastisols can be applied with different doctor blade technology, reverse roll coater coating or rotary screen printing Backing materials are processed to the composite materials according to the invention.

With the method according to the invention, the production of intumescent and, if necessary, expansion pressure and water-resistant, highly flexible and dynamically resilient composite materials that meet the international requirements with regard to flame resistance and whose thermal foam in the event of fire is so sustainably supported by the other composite components that the functionality of it equipped components can be guaranteed.

The invention further relates to all masses and composite materials that can be produced on the basis of the plastisols according to the invention and to their use in structural fire protection. The technical utilization possibilities of the invention are to be explained on the basis of the following examples, without these being able to approximate the potential range of applications.

example 1

An intumescent 300 kg plastisol batch was made as follows.

67.5 kg of Disflamol TKP plasticizer (tricresyl phosphate) and 6 kg of Solvenon PM (methyl propylene glycol) were placed in a high-speed stirrer. Under moderate revs from 300 to 400 / min. 121 kg of aluminum trihydroxide (mixture of the types Apyral 1, Apyral 15 and Apyral 25), 3 kg of zinc borate and 3 kg of the Sn (0) stabilizer are now added in portions. Then the whole thing at revolutions of 1800 / min. stirred intensively for approx. 8 minutes, then the revolutions of the dissolver disc to approx. 500 / min. shut down and the mixture was supplemented with 32 kg of expandable natural graphite (type Luh with at least 95% C) and stirred for a further 3 minutes at these revolutions.

The homogeneous, free-flowing mixture obtained is then transferred to a planetary stirrer and, with the addition of 67.5 kg of PVC powder (type Hostalit P 4472), worked up to give a plastisol which can be squeegeeed. The stirring times in the slow-running planetary mixer should be at least 30 minutes. The plastisol mixture obtained is filtered in a known manner through a 0.30 mm sieve and deaerated under a vacuum of approximately 20 mbar. The proportion of fire protection properties is 52% by weight and taking into account the Sn stabilizer, which is also fire protection, but in particular has smoke-suppressing properties, even 53% by weight.

The finished plastisol is now applied to a 1 m wide microlith SH 41/1 type glass fleece with a layer thickness of 1 mm using a cylinder knife doctor device and gelled in a 10 m long convection oven.

The feed rate is 1 m / min. and the oven temperature is 120 ° C. The approx. 1 mm thick, asymmetrical fire protection membrane has a basis weight of approx. 1.4 kg / m² and can be used in this form in light fire protection components. However, there is also the possibility of producing a double web using the reverse process, in which, in a further process step, an approximately 1 mm thick plastisol layer is knife-coated onto the nonwoven side of the web and the whole thing again in a convection oven at 140 ° C. and a feed of 1 m / min. is gelled. The 1 m wide double track obtained in this way has a thickness of 2 mm, which corresponds to the standard thickness usual in structural fire protection.

The black, smooth fire protection membrane is flame retardant (classification B 1 according to DIN 4102 - fire shaft test or M1 according to NF 92-503 "Essai au Bruleur électrique"). The foaming factor, according to DIBt guidelines / 400 ° C, 20 '/ is> 10 and the inflation pressure is approx. 0.2 N / mm².

Due to the composition, the product is waterproof (after 6 weeks of water storage, no reduction in the most important fire protection properties such as foaming behavior and expansion pressure was found) and structural fire protection is therefore a flexible product that can also be used in damp rooms or outdoors. In the latter case, however, direct weathering should be avoided.

The web can also be cut into fire protection strips or tapes with roller knives. Such strips with the dimensions 7 x 2 mm have been successfully tested in fire-retardant fire protection doors T-30 and with the dimensions 15 x 2 mm in T-60 doors.

Example 2

An intumescent plastisol batch in the order of magnitude of 300 kg was provided analogously to Example 1.

67.2 kg of Disflamol TKP and 6 kg of Solvenon PM are placed under the dissolver as before. With moderate revolutions (300 - 400 / min.) 159 kg of a powdered fire protection mixture consisting of ammonium phosphate, polyalcohol and dicyandiamide and 0.6 kg of iron oxide brown 3298 are now added in portions and at revolutions of 2000 rpm. dispersed intensively for approx. 8 minutes. The temperature of the mixture rose from 22 ° C to 31 ° C. After decanting into a slow-running planetary mixer and cooling to 22 ° C, 67.2 kg of the PVC powder Hostalit P 4472 can now be added and stirred for 30 minutes.

The brown, squeegee paste contains over 53% by weight of fire protection components and, as before, was knife-coated onto a 1 m wide glass fleece of the microlith SH 41/1 type and worked up in reverse to a reinforced fire protection sheet of 2 mm thickness. The basis weight of the web is approx. 2.5 kg / m², the foaming factor> 11 and no significant inflation pressure was measured. This composite material was also used to demonstrate flame retardancy in accordance with the requirements of DIN 4102 and NF 92 - 503. However, the fire protection components here consist of partially water-soluble components, so that they cannot be used outdoors or in damp rooms.

Example 3

An intumescent plastisol with strong expansion pressure properties is provided as follows.

A plasticizer mixture consisting of 48 kg Genomol TBEP (tributoxyethylphosphate and 24 kg Santicer 148 (isodecylphosphate) are added in portions under the dissolver 165 kg expandable graphite of the type Tropag - MBS and 3 kg of the Sn (0) stabilizer and at approx. 1500 rpm dispersed for about 5 minutes.

After decanting into the planetary mixer, the graphite dispersion is supplemented with 42 kg of Hostalit PA 5470/5 and 18 kg of Hostalit SA 1062/7 and stirred for 1/2 hour.

The highly concentrated intumescent paste obtained, with a content of fire protection components of 56% by weight, is then knife-coated onto a special carrier fleece with a layer thickness of 1 mm and in a convection oven at a feed rate of 0.8 m / min. and gelled at 140 ° C. This carrier fleece consists of a 15 mm thick aluminum foil, on the one hand with a polyester layer and on the other is laminated with a polyethylene layer, in which a polyester fleece reinforcement of approx. 40 g / m² is integrated. An approximately 1.2 mm thick plastisol layer is doctored onto the latter and gelled. With a total thickness of approx. 2.1 mm, the layered composite material produced in this way consists of a total of 5 layers and has a number of technically very interesting properties.

The foaming factor, measured after 20 minutes at 400 ° C, with a load of 5 g / cm² is approx. 45, without load it even reaches values above 60. The expansion pressure here reaches values of more than 1.2 N / mm², which is not even approached by any current market product. The wash-out rate after only 6 weeks' storage in water was only 0.6% by weight, which had no effect on the foaming, and even slightly improved values could then be measured at the expansion pressure. This product can also be used outdoors because the weather-resistant aluminum foil provides effective surface protection.

Due to its extraordinary expansion pressure properties, this product is particularly suitable for use in fire protection collars and other shut-off devices that are triggered in the event of fire by the expansion pressure.

Example 4

An intumescent plastisol with a particularly high foaming behavior can be provided as follows.

A plasticizer mixture consisting of 48 kg Genomol TBEP and 24 kg Santicer 148 is added in portions under the dissolver with 125 kg of a powdery basic fire protection mixture (ammonium phosphate, polyalcohol and dicyandiamide) and 40 kg of Madurit 150 MW (melamine-formaldehyde resin) and added at 1800 U / min. dispersed for about 8 minutes. After cooling to 20 ° C and decanting into a planetary mixer, the dispersion can be supplemented with 42 kg Hostalit PA 5470/5 and 18 kg Hostalit SA 1062/7 and stirred for a further 1/2 hour. After filtration and deaeration, a fire protection membrane can be produced by scraping onto a microlith SH 50/2 glass fleece in the reverse process, in which case one can start from an analogous product to the membrane produced according to Example 2. Compared to the latter, the new membrane has a lower basis weight (approx. 2.2 kg / m²), but the same fire classification (B1 according to DIN 4102 and M1 according to NF 92-503) shows a diametrically better foaming behavior. According to the DIBt guidelines, values of over 40 were measured at 400 ° C after 20 minutes with no load.

Example 5

An intumescent plastisol approach of the order of 300 kg can be provided analogously to the previous examples, using the following recipe: 1. Genomol TBEP 50 kg 2nd Santicer 148 12 kg 3rd Solvenon PM 6 kg 4th Boric acid 103 kg 5. Ammonium phosphate 20 kg 7. Expandable natural graphite (Luh type) 30 kg 8th. Hostalit P 4472 72 kg

The finished intumescent plastisol is doctored onto a 4-layer carrier web at approx. 2.2 kg / m². This carrier web has a structure similar to that already described in Example 3, with the difference that an approximately 50 g / m 2 thick glass fleece is integrated into the PE layer instead of the polyester fleece. In the Mohr type convection oven, at an oven temperature of 120 ° C and a feed rate of approx. 0.9 m / min., Good gelation could be achieved and the finished sheets then in sections of 10 m. are made up as rolled goods.

The completed, highly flexible fire protection vapor barrier was successfully tested at the research center for fire protection technology at the University of Karlsruhe in accordance with the requirements of DIN 18234 Part 1, "Structural fire protection in industrial buildings; roofs". The tested flat roof structure consisted of trapezoidal profile sheets, the fire protection vapor barrier according to the invention, a 100 mm thick thermal insulation made of polystyrene panels and 2 layers of bituminous welding sheets. This roof structure contains over 12 kg of flammable products per m².

A burnout can be successfully prevented by the protective effect of the fire protection vapor barrier used. 40 minutes after the fire load was ignited and after the temperature in the fire room had risen to approx. 1000 ° C in the meantime, the fire test was successfully concluded with the result "no burnout".

Furthermore, possible uses of this product for the extensive fire protection of dangerous goods containers were tested. Two webs were assembled with a central wire mesh to form a flexible, mechanically very resistant system and subjected to a component test in accordance with DIN 4102 in a small fire furnace. After 90 minutes of exposure according to the standard temperature-time curve was a max. Temperature of 260 ° C and measured as the average of all measuring points 210 ° C.

Example 6

20 mm thick wire mesh mats are impregnated with a plastisol manufactured according to Example 1 and thermally gelled after dripping. The coating increased the basis weight of the mats by approx. 3 kg / m². Two of these mats were joined together with 10 mm thick spacers to form a flexible, mechanically heavy-duty fire and noise protection element.

In a fire test carried out analogously to Example 5, after 90 minutes outside measurements only 180 ° C as the maximum value and 148 ° C as the mean value of all measuring points.

Example 7

Analogously to Example 6, an 18 mm thick PPI plastic mat is impregnated with the intumescent plastisol according to Example 1. This coating increased the basis weight of the PPI mats from originally 0.5 kg / m² to 2.5 kg / m².

Two of these mats were joined together with a central 3 mm thick wire mesh to form an approx. 40 mm thick fire and noise protection element.

The fire test carried out according to Examples 5 and 6 gave a maximum value of 250 ° C. and an average value of 230 ° C. after 90 minutes on the outer panel.

Example 8

A highly concentrated plastisol is prepared as described above based on the following recipe: 1. Genomol TBEP 48 kg 2nd Santicer 148 24 kg 3rd Raw vermiculite 45 kg 4th Melamine phosphate 63 kg 5. Boric acid 27 kg 7. Expandable natural graphite (type "Luh") 15 kg 8th. Stabilizer ST (0) 6 kg 9. Hostalit PA 5470/5 48 kg 10th Hostalit SA 1062/7 24 kg

This plastisol is then knife-coated and gelled in reverse on a UC 300 PB type of glass roving. Hollow bars made of aluminum are integrated as stiffening elements at intervals of 30 - 40 cm in the obtained, highly flexible, dynamically strong fire protection membrane.

The opening of the small furnace was closed with this track and thermally stressed with the standard temperature-time curve. The burnout occurred in the upper corner area of the test specimen after 38 minutes.

In another fire test, in which the rolled-up fire protection membrane was positioned as a fire protection roller shutter between 2 F panes, a standing time of 36 minutes could be achieved. This track can therefore be used in the form of fire protection roller shutters to divide fire sections in companies where a stationary fire protection wall cannot be created due to manufacturing reasons or for the provisional shielding of danger zones and dangerous goods stores. A completely different aspect is the use of these roller shutters as an integral part of light fire protection glazing.

Example 9

Insulating half-shells made of open-pore melamine resin foam (Basotect - BASF AG) are coated with the intumescent plastisols according to Example 1. The average order quantity is approx. 700 g / m². After gelling, the half-shells have a highly flexible, flame-retardant, waterproof outer skin, which enables them to be used even in damp rooms.

Example 10

Bead insulation wedges made of phenolic resin foam are coated analogously to Example 9 with the intumescent plastisol according to Example 1. Corresponding fire tests with flat roof systems have shown that the thermal foam created under the action of heat compensates for the shrinking foam volume and thus prevents the occurrence of flammable gases, secondary sources of fire or explosive gas mixtures in the event of fire.

Example 11

Two rectangular tin cans for flammable liquids with a filling capacity of 10 liters were prepared for the following comparative tests.

The outside of the first canister was coated on all sides with a commercially available underbody protection based on PVC plastisol, the second analogue with an intumescent plastisol according to the invention having the following composition: 1. Genomol TBEP 19% by weight 2nd Santicer 148 10% by weight 3rd Melamine phosphate 18% by weight 4th Barium borate 12% by weight 5. Expanded mica 6% by weight 6. Expandable graphite Tropag MBS 4% by weight 7. Stabilizer Su (0) 2% by weight 8th. Hostalit PA 5470/5 18% by weight 9. Hostalit SA 1062/7 11% by weight

The coating thickness was 2 mm in each case. The canisters, half filled with 5 liters of water, were placed in a small fire oven on a wire frame in such a way that they were flamed concentrically by 4 large-sized gas burners.

After the burners were ignited, it took 3 minutes and 40 seconds for the water in the first container to reach the boiling temperature, while this took over 12 minutes in the fire-protected canister. This simple experiment was intended to roughly simulate the conditions that cause the fuel tank to burst or explode in a motor vehicle accident when the fuel is ignited.

Example 12

The composition of the intumescent plastisol from Example 11 is changed such that the proportion of barium borate is reduced to 6% by weight and replaced by zinc borate with 4% by weight, zinc oxide with 1% by weight and azodicarbonamide with 1% by weight becomes.

The plastisol according to the invention is knife-coated on kraft paper with a thickness of approx. 0.7 mm and in a convection oven at 170 ° C. and a feed of 1.2 m / min. foamed and gelled. The layered composite foam obtained can include used as packaging material for explosives and ammunition.

Claims (16)

Process for the production of fire-resistant composite materials using highly concentrated intumescent plastisols, characterized in that the fire protection components are first dispersed in the plasticizer in a high-speed mixer and the homogeneous paste obtained, if necessary after cooling by adding synthetic resin in a slow-running mixer, in a highly concentrated Intumescent plastisol is transferred. A method according to claim 1, characterized in that the fire protection dispersions are preferably provided in a dissolver mixer, in the range from 1000 to 2000 rpm. and their conversion into highly concentrated intumescent plastisols preferably takes place in a planetary stirrer at revolutions of ≦ 100 rpm. Method according to claims 1 and 2, characterized in that the intumescent plastisols are filtered and deaerated, if necessary, by methods known per se prior to their further processing. Process according to Claims 1 to 3, characterized in that, depending on the intended area of application, the fire protection components are composed of a mixture of intumescent, ablative (water-releasing) and, if appropriate, also components which develop expansion pressure. Process according to claims 1 to 4, characterized in that mainly mixtures based on salts of phosphoric, boric or sulfuric acid are used as intumescent components. Process according to claims 1 to 4, characterized in that the ablative constituents include artinite, alumohydrocalcite, benzoic and salicylic acid, beryllium biacetylacetate, dansonite, ettringite, hydromagnesite, hydrotalcite, magnesium hydroxide, nesquehonite, p-dichlorobenzene, zeolite, zirconium (IV) , Zirconyl chloride preferably aluminum trihydroxide and / or dimelamine pyrophosphate can be used. Process according to Claims 1 to 4, characterized in that expanded mica, perlite, raw vermiculite, borophosphates, preferably expanded graphite, can be used as the components which develop the expansion pressure. Process for the production of highly flexible layered composite materials according to Claims 1 to 3, characterized in that the intumescent plastisols are knife-coated onto a flat carrier web once or, if necessary, several times using a cylinder / knife device and then gelled and / or hardened by heat. A method according to claim 8, characterized in that nonwovens made of inorganic fibers are preferably used as the flat carrier web. Process for the production of fire protection vapor barrier sheets, according to claims 8 and 9, characterized in that a metal foil, preferably aluminum foil, is contained in the flat carrier sheet. Process for the production of highly flexible, intumescent fire and soundproofing elements by applying the intumescent plastisols according to claims 1 to 3 to non-thermoplastic, open-pore structures such as mats, nets, cassettes, foams and the like and then gelling or hardening them by the action of heat. Process for the protection of dangerous goods containers such as chemical containers, motor vehicle tanks, also in the form of underbody protection and sealing compounds, characterized in that intumescent plastisols according to claims 1 to 4 are applied to the surfaces to be protected and then gelled or hardened under the action of heat. Process for the production of flexible, intumescent foams, characterized in that the intumescent plastisols according to claims 1 to 4 are first foamed cold by adding 2-3% by weight of soap and / or silicone foaming agent and then thermally gelled or hardened. Process for the production of flexible, intumescent foams, characterized in that a chemical blowing agent, preferably azodicarbonamide, is additionally added to the intumescent plastisols according to claims 1 to 4. Process for the production of fire protection wallpaper, according to claims 13 and 14, characterized in that the foamed masses are shaped by heated embossing rollers. Use of the composite materials and intumescent plastisols manufactured according to claims 1 to 15 in structural fire protection.